Hair is damaged by living environments (UV and heat from sunlight, drying), daily hair-care actions (hair washing, brushing, heat by drier) and chemical treatments (coloring, perming, etc.), and hair is kept in friction with each other while wetted, the surface thereof receives a great frictional force so that, while in hair washing, hair would generate a feeling of squeakiness and a feeling of entanglement. In a hair-care composition, in general, a cationic polymer such as typically a cationized hydroxyethyl cellulose is incorporated for the purpose of securing good finger-combability, smoothness and good slip retention in rinsing, in addition to securing the basic function thereof of washing away the dirt from hair as a conditioner composition.
For example, PTL 1 discloses hydrophobe-substituted water-soluble cationic polysaccharides, and in Examples therein, there are exemplified water-soluble cationic polysaccharides that are produced by reacting a cellulose-type starting substance with glycidol followed by quaternizing/alkylating it. The literature further says that aqueous solutions of the cationic polysaccharides enable powerful viscosity increase and foaming, and are therefore useful as hair-care compositions such as shampoos, hair conditioners, etc.
PTL 2 discloses a cellulose ether substituted with a substituent containing an alkyl or arylalkyl group with from 8 to 24 carbon atoms and a quaternary nitrogen-containing substituent, in a ratio of from 0.0003 to 0.08 mol per mol of the anhydroglucose unit therein, and a hair-care composition such as shampoo and the like containing the cellulose ether, further illustrating that the hair-care composition can better the combability of hair in wet and in dry. PTL 3 illustrates a hair-care composition containing a cationized glycerolated cellulose in which the mean addition molar number of the cationic group is from 0.2 to 0.5 and the mean addition molar number of the glycerol group is from 1 to 2.58, saying that the composition can better the combability of hair in hair washing.